person - could it mean a person as in you or I as we study; does it mean that a person and heart shall be connected in the meaning becoming "one" or the "same" as heaven, heaven and earth, or heaven or earth. The character, of which I am not well versed, may not mean exactly person.
heart - could it mean literally the heart since the heart is responsible for pumping the blood and energy through out the body, i.e. cycles of the blood pumping like the cycles of the heavens or the earth in relation to the heavens; or could it be a way of saying "spirit" for to forge the spirit is a part of the "way" and since they refer to the heavens and earth in a non-literal way, or do they, then heart may have some symbolic meaning we are not privy to since we are not the originators of this pome.
same - Since there are not connectors in this type of communications we can not be totally sure that the character refers to "same" or a so called comparison of person | heart to heaven | earth. The character may have a totally different meaning in the context of which it was written.
heaven - could it be a literal meaning of the heavens above us in the sky/night or is it symbolic; is it connected to the "earth" literally to provide a dual meaning to point to a person's heart or spirit or ...; could it be symbolic to an ideology related to Taoism or Confucianism...
earth - could it be as simple as the meaning of heaven in relation to stressing a type of meaning with the rest of the translation or are the characters to stand alone.
In the end I believe that they are all meant to be connected like the strings of energy in our universe as explained by the string theory. I believe every thing is connected in a manner which could be construed as a connection of energies such as in this string theory.
If we accept the translation into English and try to understand it then we need to do a few things first such as find out what the original translator was thinking and feeling along with his customs and practices as influenced by his religion, history, local, customs of the local/country, etc. One of the concepts Tatsuo Sensei mentioned to his son Shinsho as well as Advincula Sensei was the importance of following the gokui with one concept being to "learn about others customs."
Since a lot of Okinawa customs were influenced greatly by the Chinese and it is understood, if un-provable, that the old masters studied the Chinese classics then how do we connect that to the meaning when we see "heaven and earth" in the pome.
This further solidifies the concept and desire of Tatsuo Sensei that we learn about a persons customs and history, etc. for we truly can not fully comprehend the pome with out that data.
Something to think about don't you think?